Tracker Seadoo Jet Jon Build

[bdeemo]

Hey Guys, so I didn't realize how many jet jonners there was on here. I thought it would be cool to post my build. I started in July last year, but then had to go to college for my last semester, and got busy with other stuff. Last week, though, I picked up my project again and I'm getting really near the test run. I've done a lot of work on this thing, and now its not that its not going to work, I'm going to MAKE it work one way or another. Wayyy too far in it now, but its crazy I haven't ran the thing yet.

I'll post some pics up and keep you guys content to view.

 

[bdeemo]

Here is my boat, a 2005 1448 tracker grizzly... I use it to go bowfishing, hence the front deck


And work begins ripping out the guts of the boat


I was able to sell that 25 horse evinrude long shaft for $800 with the controls

 

[bdeemo]

The donor ski: a 1995 seadoo xp. I picked it up on craigslist for $250. (Ran the numbers and surprisingly it wasn't hot) but it had no title, which was no big deal to me. For those of you who are not familiar... this year make model has the 720 rotax engine, a beast of a two stroke two cylinder, which makes a mean 85hp at only 85 lbs! This is crazy when comparing to my outboard, 115 lbs at 25hp.

I took the ski to the lake the day I bought it, and was happily scooting around at 55 mph. It ran FLAWLESSLY. Man did I get a steal. The guy was really hurting for money and had it up on craigslist for $550 and I was able to chew him down to $250. This was the entire reason I started this build.

 

[CedarRiverScooter]

How did you get those tools to hang upside down like that - JK!

 

[Capt1972]

Are you from Australia?

 

[bdeemo]

How did you get those tools to hang upside down like that - JK!

Haha!!! So frustrating. They actually come up like this because apparently my iphone was upside down when I took them

 

[bdeemo]

Are you from Australia?

Northern California

 

[bnt5]

I thought the Orient was upside down....ya know if you dig deep enough a Chinese person will come out of the hole ...so much for that reasoning!

I will watch this build since I want to build another based on the tracker grizzly hull, they seem to ride nicely and are reasonably priced.

 

[bdeemo]

Guys, I'm sorry about the upside down pics but don't have a way to change them right now with my pc situation. I took them all a long time ago before I realized they were upside down haha

Oh man.... that back bench was a real PITA to get out!!!! I remember it taking me hours.


All cleaned up, pressure washed and ready for transformation. This was a really cool experience for me, having a "blank slate" for which I could completely customize my boat. Doing everything and having everything exactly where I wanted it. I've used this boat long enough to know exactly where it handles weight the best. Having my boat for bowfishing, my weight distribution needs to be much different than most boats. When we bowfish, its usually my brother and I standing on the front deck trolling around... this is 90% of what we are doing. First of all, my front deck is all aluminum for weight, so it weighs about 80 lbs. Put that, and my brother and I on the front of the boat and thats about 450 lbs on the nose of the boat. In order to counterbalance the weight, we needed to have everything as far back as possible. Batteries and gas tank were in the VERY rear, and that was the best setup that I found. It wasn't only the way that we fished, but the design of the hull. There is much more surface area touching the water in the rear, so the front naturally sits low.



Hacked the ski in half, mostly using a sawzall, but a grinder in some places. I had to be careful to not cut any wires/fuel lines etc.




The intake/motor mount I was able to cut out a little large, and I trimmed as needed later

 

[bdeemo]

Some more background: Sorry that I'm jumping all over the place, just trying to get this posted so you guys can see it. In bowfishing, all we chase here in nor cal is carp. Carp like to hang out in shallow areas, such as sloughs, swampy rivers etc. These places are really hard to get to, and we were not able to make it to a lot of them with our 25 horse outboard. The 25 horse outboard would plane out my brother and i with all of our gear at about 25mph. That felt really fast in a little boat, kind of scared of what might happen now!!! haha.

So I decided to use this method: cutting a hole in the boat, dropping in the existing jetski hull, sealing up with 3m 5200 and 1/4" ss bolts.
Of course after reading a lot of threads of jet ski jons such as psg's and ranchero's.

The most helpful thread I found was Ride_Klein's as it was the most similar application to my method of installation. Thanks man your thread helped so much!

Onto the build: Placed the cutout for the jet pump housing / motor mounts in the boat about where it would sit.




Cut the hole in the boat, started smaller than I needed then worked my way out. Measure 3 times, cut twice. haha. Scarrry


Transom from the inside. Had to hack up the bracing, for those of you considering doing this on a tracker grizzly, prepare for a PITA with the transom, those things are STRONG

 

[CedarRiverScooter]

Looks good, your MV will perform much better than a straight flat bottom.

 

[bnt5]

please let us know how the boat performs, very interested in this hull design.

 

[bdeemo]

Had to do a lot of trimming, both on the fiberglass ski hull, and on the aluminum jon hull.

This is how it looked from underneath



My man Rory from work. helping out with the trimming and fitment


Now that we had the ski fitting in the hole how we liked it, it was time to make a flange. Layed down some tape on the boat hull

 

[bdeemo]

Lots of tape and shims, getting it RIGHT to where we wanted it. I made the entire ski hull a tiny bit lower than the boat. This allowed me to easily make a more natural spoon to help with cavitation. I'll show that later.




Once it was set, we used the tape to act as a barrier to stop our bondo glass from going any further(like a dam) We made this dam on the inside of the boat all the way around the fiberglass insert, then just shoved bondo glass into the hole from beneath the boat, letting it dam up on the tape and create a flange. We also put down a flat piece of aluminum and glassed over the top of it later, and used bolts.

Flipped the boat over the next day and filled the bottom side with bondo glass

 

[bdeemo]

As you can see from above^ those of you who are thinking of using this hull for a jet jon, the hull seems to be the perfect hull. No center keel is a big advantage. I don't expect my boat to cavitate. It seems to have been MADE for this!!!

 

[bdeemo]

Now that I had the shape I wanted... it was time to sand the whole thing a little low to make room for the fiberglass to go over it for strength.



Now time to fiberglass... one side here:

other side:


I did a couple of coats of glass.

 

[bdeemo]

Next up: I cleaned up the fiberglass piece, (Got too messy with the resin ill admit) had to scrape a bunch of resin off and sand down the whole thing so it was ready to adhere. Then cleaned the whole thing with wax and grease remover, and ground down the boat real well / cleaned very good. Next we just layed a thick bead of 5200 around the whole thing(went through 6 tubes of the stuff) and set the fiberglass in / tightened our 1/4" stainless bolts/nylocs. The bolts squeezed out the caulking really well so we knew we had a good seal. I found that the cheapest place to buy 5200 was at lowes for like $12 a tube.




Forgot to show a pic of this: I also took some aluminum angle, cut one side of it in two places, and bent it / welded it around the hole in the transom for a flange to work with bolting/glueing on the jet pump housing. Heres how it turned out:

 

[bdeemo]

Water test time! About a week later i threw it in the pond, found two main leaks.

On each corner of the jet pump housing. (Which means it was seadoo's fault, not mine!

 

[bnt5]

You might want to consider glassing the bottom of the jetski hull to the aluminum boat hull. I found that the amount of stress placed on the splice between both hulls is pretty tremendous and will want to separate with time. I used 3 layers of 20oz fabric epoxied to the bottom of both hulls to strengthen the joint and give an extra thick layer of protection in case of bottom collisions. Just a suggestion, and you might be perfectly fine with the 5200 and carriage bolts but the fiberglassing is always an option down the road.

 

[CedarRiverScooter]

looking great!

I'm in the camp that fiberglassing to aluminum won't hold up, at least up in the north woods. The thermal expansion rates of Al & plastic are drastically different. The best plan is to have an elastic joint that can handle the resultant shear forces (such as 5200).

I was going to use 'Marine Tex' to bond my ski insert to the alum hull but the guy at Marine Tex said it would crack eventually.